Brake



April l1, 1939. o, RAsMussEN E1' AL. 2,154,074

BRAKE Filed Sept. 29, 1957 f Gttornegs Patented Apr. 11, 1939 UNITEDSTATES PATENT OFFICE BRAKE Application September 29, 1937, Serial No.166,247

1 Claim.

This invention relates to brakes, and particularly to brakes `as used onthe wheels of motor vehicles.

The invention, furthermore, relates to a kind of brake wherein opposedshoes are expanded into contact with the drum by floating applying meansand in which said shoes are so anchored that they readily conform to thecontour of the drum, and wherein changes in the anchorage take placeautomatically to accommodate changes in the vcoeilicient of frictionbetween the lining of the shoes and the drum surface.

An object of the invention is to provide a very simple adjusting meansfor such a brake to accommodate lining wear.

Other objects and advantages will be appreciated from the followingdescription.

Infthe accompanying drawing Fig. 1 is a View in elevation of the shoeassembly.

Fig. 2 is a section on line 2-2 of Fig. 1. Fig. 3 is a sectioncorresponding to Fig. 2 but showing a slight modication.

Referring by reference characters to the drawing, numeral 1 is used todesignate a drum rotatable with a wheel (not shown). At 9 is a xed plateserving as an anchorage to receive the torque of brake application.Numerals II and I3 are used to mark the two shoes which are to be spreadinto contact with the drum. The applying means includes two pistons I5operable within a wheel cylinder I1. This Wheel cylinder need not bedescribed inasmuch as it is the part of the conventional hydraulic brakeapplying means. Numeral I8 is used to designate the lining on 35 the twoshoes. A retracting spring is shown at I9, this spring being used towithdraw the shoes from contact with the drum after the brake has beenapplied. The anchorage plate 9 is formed to receive the thrust ofarticulating links 25. The

40 thrust means includes plates 21 which are secured together, with aclosure plate 29, to the plate 9 by fastening means 3|.

Each link 25 is formed of two axially aligned parts 33 and 35. Theseparts are externally 45 threaded with right and left hand threads andcoupled by an internally threaded sleeve 31. The end of part 35 is:rounded and received in socket 23. Part 33 is hollow and its end isflattened so that its side walls 4straddle the web 39 of the 50 shoe andare pivoted to the web at a point between the center of the are of theshoe and the end 40. A shouldered pivot pin 4I passes through suitableapertures in the web of the shoe and the walls of the part 33. Adjacentone wall of part 33 is a. washer 43 received within a slot 45 of the(Cl. 18S-79.5)

pin. Engaging the other Wall of part 33 is a stamping 41, itself engagedwith one end of a coll spring 49, the latter being in abutment with awasher 5I held by another slot in the pivot pin. Stamping 41 isangularly shaped as shown in the drawing yand its end is indented as at53 to engage teeth 55 formed on a radial flange of the sleeve 31. Thefixed abutment plate 9 has a covered opening 51 to aiord access to theteeth 55.

As stated above, the invention provides a convenient means for adjustingthe clearance between the lining of the shoes and the inner surface ofthe drum annulus.

The adjustment described is` particularly useful for a brake of the kinddescribed where the rotation of the shoes to effect braking action isaccomplished by a rocking of the rounded end of the link in the socket23, but wherein, in the event of changes in the coefficient of frictionbetween the lining and the drum resulting in a change in the ratiobetween the applying force and the force of self-actuation, there willbe more or less rotation about the pivot 4I to so correct the ane gularmovement between the shoe and the link as to relocate the high pressurepoint along the arc of the shoe and to most effectively distribute thebraking action. With such a shoe assembly it is found very convenientmerely to extend the length of the articulating link to offset wear ofthe lining carried by the shoe. Such an adjustment is easily made byengaging a suitable tool with the teeth 55, the tool being projectedthrough the opening 51.

In Fig. 3, part 35 is soeketed as before in part 21 between the plates 9and 29. It has an enlargement or flange 6I engaged by a. sleeve 63threaded upon the -aligned link 65. This latter is tubular in form andadapted to receive the end 61 of part 35'. Its pivot end portion isrelated to web 39 in the same way as is shown in Fig. 2. The shoulder 69of pivot pin 1I engages the end of a modified stamping 41 which isrelated to the teeth 13 of sleeve 63 as before described. 'I'he teethare reached through an opening 51 -as in the form previously described.The pivot pin has a slot 15'seating a ilat spring 11, engaging a at face19 at the end of part 65, serving in this Way to hold the partsresiliently in frictional contact. Rotation of sleeve 63 on part 65serves in an obvious manner to vary the length of the articulating linkconnecting the shoe and the plate 9.

We claim:

A brake mechanism comprising a xed backing plate, a rotatable drum, apair of shoes to engage the drum, floating applying means between onepair of adjacent ends of said shoes, means to anchor said shoes on saidbacking plate, said anchoring means; consisting of links pivoted to saidbacking plate and to said shoes, the pivotal connection with said shoesbeing between their centers and their opposite ends, said links beingadjustable in length, together with yielding means effecting frictionaldrag adjacent the pivotal conneotion between each link and the shoe, anelement through which said yielding means operates as stated, saidelement also functioning in addition thereto to retain said links inselected positions of adjustment.

OLAF RASMUSSEN.

GILBERT K. HAUSE.

